Fluorosulfuric acid aromatic-ring esters are useful as low-cost substitutes for trifluoromethanesulfonic acid aromatic-ring esters (Non-Patent Document 1). As typical production processes of fluorosulfuric acid aromatic-ring esters, there are known a process for producing a fluorosulfuric acid aromatic-ring ester by thermal decomposition of an arenediazonium fluorosulfate (Non-Patent Document 2), a process for producing a fluorosulfuric acid aromatic-ring ester with the use of sulfonylchloridefluoride (SO2ClF) (Non-Patent Document 3) and a process for producing a fluorosulfuric acid aromatic-ring ester with the use of fluorosulfuric acid anhydride (Non-Patent Document 4). There is also known, as a technique relevant to the present invention, a process for producing a fluorosulfuric acid aromatic-ring ester with the use of sulfuryl fluoride (SO2F2) (Patent Document 1).